Offshore power conversion apparatus

ABSTRACT

An apparatus located in a body of water which has a fluctuating water level for actuation of a float assembly which is coupled to fluid displacement means. Fluid is pumped to a motor during both upward and downward movement of the float assembly with said assembly being retained against lateral movement by ground engaging supports. The motor is coupled to power conversion means, as for example a generator as shown.

United States Patent Strange [54] OFFSHORE POWER CONVERSION APPARATUS Edward A. Strange, PO. Box 205, Florence, Oreg. 97439 [22] Filed: Mar. 30, 1970 [21] Appl.No.: 23,792

[72] Inventor:

[52) (J. ..60/51, 1 15/4, 60/53 R, 417/333 [51 Int. Cl ..B63h 19/02, F04b 17/00 [58] Field of Search ..417/333; 60/22, 51, 53;115/4, 115/5; 416/85, 86; 415/7; 73/320 [56] References Cited UNITED STATES PATENTS 680,357 8/1901 Rhoads ..417/333 1,504,025 8/1924 Corset ....73/320 1,822,806 9/1931 Geary ..60/22 1,523,031 l/l925 Mitchell ..417/333 2,871,790 2/l959 Weills ..417/333 589,520 9/1897 Wright ..60/22 FOREIGN PATENTS OR APPLICATIONS 566,691 l/l945 Great Britain ..417/333 Primary ExaminerCarlton R. Croyle Assistant raminer-Richard E. Gluck Auorney.lames D. Givnan, Jr.

[ ABSTRACT An apparatus located in a body of water which has a fluctuating water level for actuation of a float assembly which is coupled to fluid displacement means. Fluid is pumped to a motor during both upward and downward movement of the float assembly with said assembly being retained against lateral movement by ground engaging supports. The motor is coupled to power conversion means, as for example a generator as shown.

1 Claim, 3 Drawing Figures PATENTED MAY 2 3 m2 FIG. 1

INVENTOR EDWARD A. STRAmE i AT PATENTEnmzs I972 PYSHEEIZOIFZ I INVENTOR EDWARD A. STRANGE AGENT OFFSHORE POWER CONVERSION APPARATUS BACKGROUND OF THE INVENTION The present invention relates generally to power conversion apparatus and in particularly to an apparatus powered by the rise and fall of the ocean surface.

To the extent known the prior art includes various arrangements for converting wave or tidal motion into usable mechanical power. Old in the art are complicated gear trains for the purpose of converting and increasing the relatively slow vertical movement of the ocean, such gear trains including a gear rack associated with a float member. Since the ultimate use of the transmitted power as shown in the art at hand is the powering of electrical generators, the required rotational speed was sought by providing a multitude of gear components constituting a very complicated and costly structure. A substantial loss of energy by reason of friction and inertia is inherent in their operation.

SUMMARY OF THE INVENTION The present invention is embodied within a structure for support on the ocean floor seaward of the breaker line in the area of ocean swell movement. While the distance ofi'shore will vary with the area geography the instant apparatus is intended for close-in, convenient location to facilitate power transmission to shore. The apparatus advantageously utilizes vertical movement of the ocean surface, such movement being provided by swells, occurring at both varying intervals and magnitude. In distinction to the devices of the prior art the continuous motion of the swells may be utilized in addition to tidal movement of the water surface.

The present invention further provides for a substantially continuous flow of fluid under pressure past a hydraulic motor in a fluid charged circuit. The motor may be usefully coupled to various power converting means as for instance electric generating equipment the details of which equipment are not part of the instant invention. A float assembly is confined for vertical rolling engagement with supports of the apparatus and which float assembly is in mechanical connection with a piston in a closed fluid chamber. Valve means in communication with supply and discharge conduits serving the fluid chamber control the intake and exhaust of fluid to assure the continuous fluid flow to the motor. Further additional valve means enable the locking of the float assembly in a raised position for maintenance to be performed as well as for other purposes.

An important object of the invention is to take advantage of the continuous swell motion of the ocean in that area closely adjacent to the shoreline. In such areas the swell movement may be conveniently converted by the present apparatus into the continuous powering of a hydraulic motor. Accordingly, and by reason of the simplicity of the apparatus, an offshore generating station may be provided at a cost making it practical for remote locations.

A further object is to provide a means for confining a float assembly against undesired lateral displacement under the influence of ocean wave movement. The force exerted on the float assembly is efficiently converted to vertical movement of the assembly for displacement of fluid within a fully charged fluid system. To utilize the water movement in a practical manner it is necessary both to minimize losses due to friction between structural components and to provide a float of a configuration to advantageously partake of the water movement. Toward this end the float assembly is constructed with friction reducing roller components and is configured to transform water motion into an upwardly inclined force vector.

A further object includes the providing of a power generating apparatus powered by ocean swell movement wherein a fluid flow within the apparatus is produced in a continuous manner regardless of widely varying water conditions.

Toward accomplishing the foregoing objects a closed float assembly is provided being very responsive to water level changes and including tubular extensions for the ultimate operation of a piston within a fluid filled chamber. Also for purposes of efficiency the float assembly is of a configuration to avoid the lifting of sea water as would occur with a flat surfaced assembly.

Valve components are of low restriction type to permit filling and discharge of the fluid chamber.

BRIEF DESCRIPTION OF THE DRAWING In the accompanying drawing:

FIG. 1 is a side elevational view of the power conversion apparatus embodying the present invention with components sectioned to allow an adequate illustration,

FIG. 2 is a sectional plan view taken along line 2-2 of FIG. 1 showing the float assembly and supports associated with same, and

FIG. 3 is a detailed view of typical roller means carried by the float assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENT With continuing reference to the accompanying drawing wherein applied reference numerals indicate parts similarly identified in the following specification, the reference numeral 10 indicates a pladorm positioned by supports 11, the latter extending downwardly into the ocean floor.

As earlier noted the platform is to be located close to shore but seaward of waves breaking on the shoreline. The supports 11 serve additionally to guide the float assembly 12 in a rectilinear, vertical path, the details of the assembly being provided at a later point in the specification. Platform 10 constitutes a base for a tower structure 13 on which a fully charged fluid chamber 14 is mounted. The support structure 13 includes inclined legs terminating at their upper ends in secured connection with a ring within which is secured the fluid chamber 14.

Comprising part of the float assembly are a plurality of upwardly extending tubular members 18 extending through openings as at 20 in platform 10 terminating in a bridge 17A in secured attachment to the lower end of a piston rod 17. A piston 19, moves within fluid chamber 14, in response to float assembly movement as transmitted through piston rod 17. Suitable rod seals are provided at 15 in bearings with a dummy piston rod 16 being journalled in the uppermost seal 15. Provided on the underside of platform 10 are a series of bumpers 22 engageable with the float assembly when at its uppermost limit to protect the same from damaging contact with the platform. Roller means associated with the float assembly as well as details of the assembly are hereinafter elaborated upon.

The hydraulic system may be termed a closed system in that the fluid chamber 14 is at all times fully charged with a recirculating supply of hydraulic fluid. A chamber supply conduit 23 and a branch at 23A provide the upper and lower ends of the chamber with a constant fluid supply from an intake 238 in reservoir 24. The supply conduit and its branched portion alternately direct fluid through supply valve means at 25-26 in communication respectively with the upper and lower ends of chamber 14. The valve means 2526 constitute check valves in that the flow of fluid therethrough is limited to flow in the direction indicated by the applied arrows. Similarly discharge valve means at 27-28 associated with the upper and lower ends of chamber 14 permit in an alternate manner the exhausting of fluid from said chamber. The foregoing valve means 25 through 28 may embody conventional check valves permitting fluid flow only in the direction of the applied arrows. The valve means 2528 may incorporate hingedly carried valve components and more accurately termed flap valves.

In communication with the discharge valve means 27-28 is a discharge conduit 32, branched at 32A and receiving an alternate flow, upon piston movement in opposite directions, from the upper and lower end of the chamber 14. The discharge conduit terminates in fluid delivery with a hydraulic motor 33 which may be of the gear type. A reservoir return line 34 for the motor exhausted fluid completes the circuit discharging at 34A into reservoir 24. An accumulator at 35 is in communication with conduit 32 by means of a conduit branch 36 and functions to receive a portion of the fluid discharged from chamber 14 during momentary pressure surges thereby dampening their effect on the motor. Similarly, a pressure relief valve 37 functions at a pre-determined elevated pressure valve to divert fluid from conduit 32 directly to reservoir 24 via a line 38.

An electrical generator 39 is shown in direct driven connection with the output shaft of motor 33 and constitutes power conversion means. With a loss of some mechanical efficiency power transmission components may be added if deemed advantageous.

A gate valve at 40 in the branch conduit 32A permits closing of the lower discharge outlet of the fluid chamber 14. The fluid so confined in the chamber upon closing of gate valve 40 will permit in retaining the float chamber at a level above its normal floating range of travel for servicing of the float assembly or other components of the invention.

Float assembly 12 comprises a closed structure confined against horizontal movement and of a configuration to lessen the impact thereagainst of waves. The structure is shown as being round in plan view having shaped upper and lower surfaces at 41 and 42. Said upper surface avoids water accumulation while the lower surface is shaped to efficiently partake of the rising and falling swell movement of the water.

As earlier noted the supports 11 additionally function to limit the float movement to a vertical rectilinear path. For such movement with a minimum friction loss I employ sets of opposed rollers 43-44, each set acting along opposite sides of a support 11 as best seen in FIGS. 2 and 3. Preferably the roller mechanism includes bearings 45 shielded from the water. One such arrangement is shown wherein walled openings 46 are provided in the float assembly with four walls 47-50 in closely spaced relationship to the corresponding support surface. Walls 47-50 have openings therein through which extends a chordal segment of the rollers 43-44. Rollers shafts 51 are journalled at their ends within the sealed bearings 45 in blocks 52. The bearings 45 and blocks 52 are supported interiorly of the float chamber by an annular partition with the outermost set of rollers being carried by the circumferential wall 53 of the float structure. Additional roller means may be utilized without departing from the instant invention.

In operation the float assembly is displaced upwardly upon the passage of a swell peak. The upward piston movement causes the intake of fluid through valve 26 behind the piston while simultaneously fluid ahead of piston 19 is being exhausted from the fluid chamber through valve 27 and to motor 33 via conduit 32. In the gear motor shown the fluid passes along the unmeshed arcs of the driven motors gears and is exhausted to reservoir 24 via conduit 34. The reservoir end 34A of conduit 34 and the intake end 238 of supply conduit 23 are closely disposed to permit the negative pressure in conduit 23 to facilitate the discharge flow of fluid along conduit 34 and thereby adding to the efficiency of motor 33.

Reversal of piston movement occurring after swell peak passage will result in a discharge of fluid past valve 28 (below the piston) while valve 25 admits a fluid flow above the piston. The continuous movement of piston 14 incident to swell passage will cause a substantially constant flow of fluid along conduit 32 to the motor 33. While swell frequency and magnitude will vary substantially, fluid flow is dependent only upon a continuously changing water level. Accordingly, the features of the instant invention may be provided on a scale to beneficially utilize tidal changes in the water level.

Having thus described the invention what I desire to secure under a Letters Patent is:

1. In a power conversion apparatus powered by the changing surface level of a body of water, said apparatus having a float assembly, a fluid chamber positioned upon a plurality of upright supports, piston means powered by said float assembly for reciprocal movement in said chamber, supply valve means regulating fluid flow In an alternate manner to admit fluid behind the piston during travel, discharge valve means permitting discharge of fluid in an alternate manner from that area of the fluid chamber ahead of the moving piston, a fluid powered motor in communication with the discharge valve means and powered by pressurized fluid discharged from said chamber, the improvement comprising an improved float assembly, said float assembly comprising, a circular float structure having a lower surface of inverted conical shape and an upper surface of domed shape, centrally disposed tubular members extending upwardly from said upper surface of the float structure and terminating in operative connection with a piston rod of said piston means, said float structure having internal walls to define at least four circumferentially spaced apart openings in said structure each opening receiving an upright support, opposed sets of rollers internally carried Within said float structure adjacent each of said openings with the rollers having chorded segments rotating through openings in said internal walls and in rolling contact with two opposed surfaces of a support to at all times space the portion of said float structure defining said openings away from said supports whereby resistance to guided vertical float movement is reduced in the presence of side loads imparted to the float by wave action. 

1. In a power conversion apparatus powered by the changing surface level of a body of water, said apparatus having a float assembly, a fluid chamber positioned upon a plurality of upright supports, piston means powered by said float assembly for reciprocal movement in said chamber, supply valve means regulating fluid flow in an alternate manner to admit fluid behind the piston during travel, discharge valve means permitting discharge of fluid in an alternate manner from that area of the fluid chamber ahead of the moving piston, a fluid powered motor in communication with the discharge valve means and powered by pressurized fluid discharged from said chamber, the improvement comprising an improved float assembly, said float assembly comprising, a circular float structure having a lower surface of inverted conical shape and an upper surface of domed shape, centrally disposed tubular members extending upwardly from said upper surface of the float structure and terminating in operative connection with a piston rod of said piston means, said float structure having internal walls to define at least four circumferentially spaced apart openings in said structure each opening receiving an upright support, opposed sets of rollers internally carried within said float structure adjacent each of said openings with the rollers having chorded segments rotating through openings in said internal walls and in rolling contact with two opposed surfaces of a support to at all times space the portion of said float structure defining said openings away from said supports whereby resistance to guided vertical float movement is reduced in the presence of side loads imparted to the float by wave action. 